Caracterização dos sistemas de produção de leite na região sul do Rio Grande do Sul: relação com a mastite e a qualidade do leite

Abstract

Given the importance of the milk chain in Rio Grande do Sul, aimed to the characterization of production systems in the southern region of the state and relate the quality of milk from cooling tanks. Questionnaires were performed with farmers and milk samples were collected for chemical and microbiological analysis. The dairy business is carried out in 26,06 ha with 8,4 cows in lactating on average. Most farms produce between 50 and 100L/day. 39,3% of the farmers manual milking their animals, only 14,2% perform pre milking disinfection, 53,9% use a cloth to dry the teats of all animals. There was a negative correlation between SCC and production (r = -0,23) and between SCC and lactose (r = -0,39) and positive between lactose content and yield (r = 0,31). Concerning microbiological analyzes, the mean scores were: Staphylococcus sp. (5,32 x106 CFU/mL), S. aureus (1,33 x105 CFU/mL), Enterobacteriaceae (1,82 x107 CFU/mL). There was presence of Escherichia coli (27,8% of farms), Streptococcus agalactiae (6,2%), S. dysgalactiae (37,2%), S. uberis (16,8%), Candida sp. (15,7%), Aspergillus sp. (5,8%) and Trichosporum sp. (3,6%). Risk analyzes showed great chances of S. agalactiae, S. dysgalactiae and S. bovis when using inadequate handling practices and poor facilities. There was a significant difference (p = 0,003) in SCC, which is enhanced when milking performed manually, which also contributes to the increased count S. aureus (p = 0,0428). Performing pre milking disinfection demonstrably reduces the counting Staphylococcus sp. (p = 0,0415). The milk produced in the region is quite contaminated and one of the causes is the inadequate milking handling.